Monash University is using robots built from Lego kits at its university open day for high school students.
Several robots are being used at the university to carry out high-level computer science concepts, such as a robot solving a maze taped out on the floor by building up an internal representation of all the walls of the maze until it finds the exit and then going back into the maze via the shortest route.
Another robot solves a Rubik’s cube using a colour sensor to scan the faces of the cube to algorithmically solve the puzzle.
Research fellow, Michael Wybrow from the Clayton School of IT, said the robots have now been used for four years at university open days.
“I'm not sure exactly how it started. I think one crafty academic convinced someone to let them have some funding to buy a few Lego Mindstorms NXT kits to play around with,” he told Computerworld Australia.
“Initially they were used by a few of us under the heading of the ‘casual robotics group’. This was a mix of staff and students who would get together every fortnight for a few hours and develop interesting projects and activities to do with the robotics kits."
The robots are around the size of a shoebox and most have been built from Lego Mindstorms NXT kits, with tape and rubber bands also used in the robots’ design.
“The robotic pieces usually involve several motors and three or four sensors — touch, light, sound, colour and ultrasonic (distance). These are controlled by a battery operated 'brick',” Wybrow said.
“This has a simple processor and a small amount of flash memory that programs can be saved to. The bricks also have USB and bluetooth connections that can be used to transfer data and programs.”
The university currently has five robots built from the kits, with the robots designed by students and staff and also internet users who have posted their designs on the web.
“This is the case with the Rubik's cube solving robot ... We have just made a few minor modifications to the robot and the code that controls it,” Wybrow said.
While each kit has been designed with simple graphical programming language, the university codes the robots in NXC.
However, the development of the robots have not been without their challenges, with the most difficult part for the team programming the robots to interact and operate in the real world.
“This can be things like requiring sanity checking to make sure that the representation of the world that the robot has - the orientation state of a Rubik's cube or the position and facing within a maze - match the real-world state,” Wybrow said.
“Also there are issues related to sensors getting strange or incorrect values or motors that move the robot less than you'd expect because they hit an obstacle or the grain of the carpet causes one wheel to be more or less effective than planned.”
This has meant algorithms need to be spot on as the robots have a limited working memory and slow processors.
Monash University plans to develop the robots further in the future, according to Wybrow.
“There are interesting technical problems to solve in working with these kinds of toy robots,” he said.
“They certainly make it easy to quickly prototype ideas and try things out. It also makes a nice challenge to do complicated things in an elegant way with the limited hardware offered by the kits. And who doesn't love playing with Lego!”
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